Trip latch for pipe tongs



Sept. 5, 1933. M HACKER TRIP LATCH FOR PIPE TONGS Filed Oct. 27, 1930 2 Sheets-Sheet 1 TRIP LATCH FOR PIPE TONGS Filed Oct. 27, 1930 2 Sheets-Sheet 2 grvuQ/YW v MARGUfi L. HAGKER F i5 6 GQ Zfiw) 1 i el mmw Elbtomua s.

l atented Sept. 5, 1933 S'E'TES 1,925,532 TRIP LATCH FOR PIPE TONGS Marcus L. Hacker, Beaumont, Tex.

Application October 27,

16 Claims.

The invention relates to an improvement. in pipe wrenches or tongs, and particularly the type which are used in and about well derricks and pipe lines.

Tongs of this type are in common use and usually comprise a handle and a plurality of jaw members which are adapted to encircle the pipe. The tongs now in use involve a latch which is carried by one jaw member and arranged to pass between two outstanding lugs on the other jaw member, so that the jaws will be firmly held about the pipe. and particularly in the drilling operations where the pipe sections are to be screwed together, it is desirable to have a tong or wrench which will release from the pipe when a predetermined torque is exerted upon the handle, so that the threads on the pipe sections will not be galled. It is with the object in view of providing a pipe tong or wrench which will release from the pipe when the maximum stress which may be withstood by the threads is approached, that the present invention has been devised. Thus, as the latch releases the tong will be freed from the pipe and injury to the threadswill be avoided.

It is one of the objects of the invention to provide a separate and individual latch which may be attached to the pipe tongs which are now in general use.

Another object of the invention is to provide a latch which .willrelease the-jaw members when a predetermined pressure is exerted upon the r a trip-latch having a slidable bolt member which may move to a releasing position.

Still another object of the invention is to provide a trip mechanism which will permit the bolt latch to move to releasing position. I It is also an object of the invention to provide a latch the pivot points upon'which the parts move will be in substantially a straight line when the latch is closed in combination with means to normally hold them in such position.

Still another object of the invention is to provide a spring pressing mechanism which is so associated with the latching device that it will normally resist tripping of the latch until a predetermined pressure is exerted upon the latch.

A still further object of the invention is toprovide a latch as a separate unit which may readily be attached or detached to various types of pipe tongs which are now in general use.

Various other objects of the invention will be readily apparent when the following description In many instances,

1930. Serial No. 491,439

is considered in connection with the accompanying drawings, wherein:

Fig. 1 is a top plan view of the latch mechanism separate from the tong and showing the trip bolt in open position.

Fig. 2 is an elevation similar to Fig. 1, but showing the bolt in retracted orclosed position.

Fig. 3 is an end View looking from the lefthand side of Fig. 2.

Fig. 4 is a top plan elevation of a modified form of the invention. l

I Fig. 5 is a section taken on the line 55 of Fig. 4, and looking in the direction of the arrows.

Fig. 6 is a top elevation of one type of wellknown' tong to which the invention has been applied.

The invention may be readily understood by having reference to Fig. 6 wherein a pipe tong or wrench 1 has been illustrated. These tongs are in general use on the market and comprise a handle 2 and a plurality of jaw members 3 and l, each ofwhich is made up of a plurality of contact pieces or adapters 5 and 6. These adapters are pivoted together at 7 so that they may en-. circle the pipe, which is illustrated at 8. A handle 9 is affixed to each of the jaws whereby they may be gripped and drawn about the pipe 8.

' Due to the fact that the jaws 3 and 4 are pivoted at difierent points, such as 10 and 11 on the handle 2, these jaws will clamp about the pipe when the handle is moved in a clockwise direction. The clamping action is caused, due to the pivotal connection therein, and the adapters 5 and 6 will then securely clamp the pipe when the ends 13 and 14 of the jaws are held together. It is usual to have a horizontal swinging latch member which has an enlarged head thereon. This latch member pivots about the pin 15 so that its head will pass between the lugs 16 which are carried by the jaw member 3. As the tongs were used before the application of my inventionthis latch member is merely a straight piece of material, and when it is desired to unlatch the tong it is necessary to remove the tension onthe handle andslack up the jaw members so that the latch member may be removed from between the lugs 16. It is understood that there are two of these lugs spaced apart to admit the latch'between them, so that the enlarged head of the latch prevents subsequentmovement of the lugs so long asthe latch is held in position. My invention, however, is arranged to be mounted on the pin 15 and be substituted for the usual latch member. i

v Fig. 6 shows my invention as. applied to, the

tong wherein the inventiois illustrated generally at 20.

By having reference to Figs. 1 and 2 the in ventionmay best understood, and includes a jaw 21. This jaw is provided with a passage 22 which is arranged to receive the pivot bolt 15.

g This jaw is formed with a horizontal extending an ear 3'? formed on the body of the latch.

portion 23, which is formed with a groove 24. This groove is dove-tailed in configuration, and arranged to receive t-..e slidable trip latch or bolt 26 which formed a dove-tailed interfitting portion 27 thereon. This bolt is shown in extended position in 1 and retracted position in Fig. 2.

The bolt 26 has an enlarged head thereon which is wider than the stem 29, so that the head may be received between the upper and lower lugs 16 which are shown .11 Fig. 5.

In the embodiment of ti trip latch shown in Figs. 1, 2, and 3 an ear is formed or connected with the bolt 26 and carries a pivot pin 31. A plurality of links 32 will pivot on this bolt, and upon the pin 33 which is carried by the head 34 of the arm 35. This arm is pivoted at 36 on This forms a linkage so that movement of the bolt 26 will cause movement of the links 32, and the arm 35, from the open position shown in Fig. l

to theclosed position shown in Fig. 2.

sleeve 41 and is norm it is subjected to any definite and predetermined pressure.

' engagement against the face 46, as best seen in Fig. 2. However, when the torque on the handle or" the tong is resisted by engagement of the jaws with the pipe to the extent that the pressure is greater than can be withstood by the spring 42 the pin 45 then causes depression of the pin do so that the arm will move outward to assume the position shown in Fig. 1. This outward. movement of the arm 35 allows the links 32 to move to an extended position which in turn permits the sliding of the bolt 26. It should be noted that the pins 33, 31 and 86 lie in approximately a straight line when the latch is closed so that there is no twisting movement on the parts and the latch will not open until these pins are moved out of alignment.

With the foregoing arrangement of the structure it seems apparent that when a pipe is being screwed into position, that the plug 43 may be adjusted for that particular size of pipe, so that a pressure will be exerted by the tong on the pipe which approximates the pressure at which the pipe sections will be tightly screwed together. When, however, this pressure is exceeded the pin will be depressed and the tong will release its hold upon the pipe so that the threads of the pipe will not be injured by the excessive power and pressure being exerted upon the tong. It is'to be understood that the tongs of the type here illustrated are usually manipulated by power about the well derrick and that the operarranged to slide in the of the drawingsator is not always able to accurately control the power which is being applied to the tong, so that in many instances the operator is not aware of the exact instance at which the joint is tightly made up, and if power is continued after this instant the threads are injured, or the surfaceoi the pipe is mutilated or in some instances the tong will break; but with my invention of improved latch, when a stress equal to that which should be placed on the joint is reached the tong will automatically release its grip upon the pipe, clue to the fact that the bolt or trip latch 26 is permitted to move to releasing position.

Figs. 4 and 5 show a modified form of the in- 'vention in which the links 32 have been dispensed with, and. arm 35 is slightly modified and is shown at 35 as having a curved cam surface which terminates in the nose 51. This cam surface is arranged to contact a roller 52 which. is mounted upon a shaft 53. This shaft 53 is car ried by the jaw 20 which is identical with the jaw 20 shown in the preceding modification. A stop lug 27 is shown to limit the outward movement of the bolt 26.

The spring pressed pin id is carried by the sleeve 41 as previously described, and contacts the pin or lug 45 which is carried by the arm'35. The operation of this entire device is the same asin the preceding figure, except the cam surface and roller have been substituted for the linkage in order to control the movement of the latching bolt 26.

In order that the trip latch 20 will not swing out of position but will at all times be retained at a point whereby it may be readily latched, a stoplug 55 has been provided which is formed with a socket 56 which normally receives a spring,

the opposite end of which abuts again t the jaw- 4 of the tong. In this manner as the latch tends to swing outwardly this spring resists the swinging movement and normally retains the latch in a position whereby it may be readily passed about the lug 16. r

While I have shown and described two forms of the invention it is to be understood that various alterations and modifications may be made thereon, and that various arrangements for controlling the movement of the trip bolt may be devised. It is intended that the latch may be mounted on any' type or tong or wrench which 1 is used about pipe, or for other similar purposes. The latch maybe readily applied to existing structures, or it may be embodied in the tong when it is originally constructed. It is also intended that'the handle 2 may be modified to take on any desired configuration so that it may be used with a makeup or'baclsout post or it may be used in the form illustrated in Fig. 6

Having described my claim is:

l. A wrench of the character described including jaw members, an automatically releasable invention what I latch mounted to connect said jaws, and means means holding said latch against release, said means being releasable in response to a predetermined pressure on said jaws.

3. A wrench including a plurality of jaw members adapted to encircle a pipe, a trip latch to couple said jaw members about the pipe, andmeans to hold said latch to hold said jaws, said means being releasable in response to torque on said wrench.

4. A pipe tong comprising jaws, a handle, and a releasable latch for the jaws, said latch including a slidable bolt, a trip arm arranged to be moved by said bolt, and a pin normally resisting movement of said arm by said bolt.

5. A pipe tong comprising jaws, a handle, and a releasable latch for the jaws, said latch includ ing a slidable bolt, a triparm arranged to be moved by said bolt, a pin normally resisting movement of said arm by said bolt, and means to adjust the compression on said pin in proportion to the torque to be exerted on said handle.

6. In a pipe tong, horizontal swinging jaws, a horizontal swing latch for said jaws embodying a slidable bolt, and means 0 erable by a predetermined torque on the tong to release said latch.

7. An automatically releasable latch for pipe tong having a plurality of jaws including, a body adapted to pivot on one of the tong jaws, a slidable bolt arranged to engage another jaw, and means carried by said body and adapted to yieldingly resist movement of said bolt.

8. An automatically releasable latch for pipe tongs having a plurality of jaws including, a body adapted to pivot on one of the tong jaws, a slidable bolt arranged to engage another jaw, means carried by said body and adapted to yieldingly resist movement of said bolt, but releasable at a predetermined pressure.

9. An automatically releasable latch for pipe tongs having a plurality of jaws including, a body adapted to pivot on one of the tong jaws, a slidable boltarranged to engage another jaw, means carried by said body and adapted to yieldingly resist movement of said bolt, and means to adjust the pressure at which said means will release.

10. A latch for tongs including a body, an arm pivoted thereto, a bolt slidable with respect to said body, and interengaging means on said arm and body to resist movement of said bolt until a predetermined pressure been exerted.

11. A latch for tongs including a body, an arm pivoted thereto, a bolt slidable with respect to said body, and interengaging means on said arm and body to resist movement of said bolt until a predetermined pressure has been exerted, whereupon said means will release said bolt.

12. A latch for wrenches including three pivot pins, links connecting said pins so that when said latch is in position to retain the wrench in pipe engaging position the three pivot pins approximately approach a straight line joining the two end pins, and a movable bolt to resist movement of the center one of said pins from the approximate straight line.

13. A trip latch'including three pivot pins disposed in approximate alignment when the latch is closed, means to normally resist movement of one of said pins from approximate alignment, but adapted to release such pin upon application of a predetermined pressure thereto.

14. A latch of the character described including a linkage operable to release the latch by a force acting in such direction as to have a component longitudinally of and also transversely .to said linkage, means to normally retain said when the latch is closed and to move out of approximate alignment when the latch moves to open position, and releasable means to resist the opening of the latch by retaining one of said pins in approximate alignment.

16. A latch including a three point linkage, three pivot pins in said linkage adapted to lie on approximately a straight line joining the two end pins when the latchis closed, said pins being adapted to move out of alignment when the latch moves to open position, and means to resist movement of one of said pins with a force at least equal to a second force which is the complement of the force necessary to retain the pivot pins in approximately aligned position against the torque exerted on the latch.

MARCUS L. HACKER. 

